Electron discharge tube adapter



Dec. 20, 1932. R D DUNCAN, JR 1,891,621

ELECTRON DISCHARGE TUBE ADAPTER Filed Feb. 25. 1930 2 Sheets-Sheet l v :1 9 iNVENTOR .0 ATTORNEY Dec. 20, R D N N JR ELECTRON DISCHARGE TUBE ADAPTER Filed Feb. 25, 1930 2 Sheets-Sheet 2 INVENTOR Robert D. Duncan,

ATTORNEY Patented Dec. 20, 1932 UNITED STATES PATENT OFFICE ROBERT D. DUNCAN .13., OF EAST ORANGE, NEW JERSEY, ASSIGNOB WIRED RADIO, INC., 01 NEW YORK, N. Y., A CORPORATION OF DELAWARE ELECTRON DISCHARGE TUBE ADAPTER Application filed February 25, 1930. Serial No. 431,116.

My invention pertains in general to adapting devices for electron discharge tubes, and specifically relates to a combined adapter and switch interposed between an electron discharge tube and a supporting socket therefor.

One of the objects of my invention consists in providing a convenient and electrically efiicient device for selectively interconnecting an electron discharge] tube, a supportlng socket therefor, and an auxiliary electrical organization.

Another object of my invention comprises, producing a combined adapter and switch of relatively small capacitance for selectively tying in auxiliary electrical circuits to an electron discharge tube circuit of certain capacitance constants, without materially disturbing these constants.

Another object consists in providing a combined adapter and switch which can be interposed between an electron discharge tube and a supporting socket therefor, thereby providing short electrical connections between the electron discharge tube, the tube supporting socket, and the switch.

I accomplish the above desirable features in a novel adapter in which a switch is combined with a mounting member used in combination with an electron discharge tube and supporting socket therefor.

In the drawings accompanying and forming a part of the specification, and in which like reference numerals designate corresponding parts throughout:

Fig. 1 is a top plan view of an adapter comprising one embodiment of my invention.

Fig. 2 is a side elevation of the adapter shown in Fig. 1.

Fig. 3 is a vertical sectional view along the line 3-3 of Fig. 1, shown in combination with an electron discharge tube and a supporting socket therefor.

Flg. 4 is a diagrammatic representation of my invention in a typical application of its use.

Referring to the drawings in detail, and particularly to Fig. 1, a group of terminal pin receptacles 1, 2, 3, 4, are disposed within an adapting member 5. These terminal pin receptacles are intended to receive and support the terminal pins, or prongs, of an electron discharge tube, and are made of a conducting material, such as brass. The adapting member 5 is composed of an insulating material, such as a phenol condensation prodnot.

A group of four terminal pins, or prongs, are positioned in the adapting member 5, be low the terminal pin receptacles 1, 2, 3 and 4. Three terminal pins 6, 7 and 9, of the said group of four terminal pins, are shown in Fig. 2. The fourth terminal pin 8 of the group of four terminal pins is shown in Fig. 3. These terminalpins, composed of a conducting metal, are similar in construction to the terminal pins of an electron discharge tube, and are intended to fit into a supporting socket for such a tube.

Referring to Fig. 2, it will be seen that a switch handle 10 is pivotally mounted by means of a screw 11 to the adapting member 5. A wiping-brush 12 is rigidly secured to the switch handle 10. Two contact terminals 13 and 14 are positioned upon the adapting member 5 in the path of the wiping-brush 12. Partial rotation of the switch handle 10 will cause the wiping brush 12 to make contact with the contact'terminal 14 or the contact terminal 13.

Referring to Fig. 3, a metallic conducting spacer 15 is secured to the wiping-brush 12, between the switch handle 10 and the adapting member 5. A metallic electrical connection 27 is provided between the spacer 15 and the terminal pin receptacle 1. Another electrical connection 25, similar to the connection 27, is provided between the contact terminal 14 and the terminal pin 6. A leadoif connection 16 is secured to the contact terminal 13. (See Fig. 2.) Additional elecher can be arranged to connect, or interconnect, the terminal pin receptacles, the terminal pins, and the switch and switch poles, in any desired electrical arrangement. An electron discharge tube 17 is shown, in its relative position, above the adapting member 5, before the terminal prongs 18 of the same are inserted into the terminal pin re ceptacles of the adapting member 5, whereas a supporting socket 19, having term nal pin receptacles 20, corresponding to the terminal pins or prongs 18, of the tube 17 is partially shown directly below the adapting member 5, in a position as before the terminal pins of the adapting member have been inserted into the terminal pin receptacles of the said su porting socket.

t is evident that the tube 17 is intended to be ordinarily used in conjunction with the supporting socket 19, the terminal pins or prongs of the tube 17 being normally inserted in the corresponding terminal pin receptacles of the supporting socket 19. However, my adapter, when mounted in the supporting socket 19, substantially provides a new supporting socket for the tube 17.

It will be noted that all ofthe electrical connections of this adapter are relatively short, and of small capacitance and, therefore, will not materially disturb the capacitance constants of a circuit between the tube 17 and the supporting socket 19 into which the adapter is interposed. Consequently, the use of a switch in close proximity to these connections makes possible the selective coupling of the tube 17 and socket 19 to auxiliary electrical organizations without disturbing the capacitance constants of the or- 'ganization of which-the tube 17 is a part,

such as would be brought about by introducing long leads between the adapter and the said auxiliary electrical organization. In the association 0 one electrical organization with another, such as a wired radio tuner with a complete space radio receiving set, where it is desired to utilize a space radio tuner as an auxiliary source of radio frequency signals, my adapter provides means for selectively t mg'in the auxiliary radio frequency input circuit to the space radio detector tube circuit without disturbing capacity effects. Such an arrangement is schematically represented in Fig. 4. n Fig. 4, the adapting member 5 1S positioned between the electron discharge tube Y17, and the supporting socket 19 of a space radio receiving set having a radio frequency input source 21, and output 22 to the audio frequency amplification stages. The wired radio frequency input source 23 and detector grid condenser 24, are shown adjacent the space radio detector tube 17. Without the use of my adapter, the terminal pins 18 of the tube 17 would normally be inserted in the terminal pin receptacles 20'of the supporting socket 19, and the circuits for the radio receiving system would thereby be completed in the usual manner. By interposing the adapterof my invention between the detector tube 17 and the supporting socket 19, it is possible to utilize, at will, either the space radio input source 21,- or the wired radio input source 23 as a source of signals for the space radio detector tube and succeeding stages of audio frequency amplifies tion. It will be seen in the diagram that the grid circuit from the wired radio input source 23 is connected to contact terminal 13 by means of the lead 16,1while the grid terminal pin receptacle 1 of the aide ter is connected to the terminal screw 11, y means of the connection 27, and the grid terminal pin 6 of the adapter is connected to the contact terminal 14, by means of theconnection 25. The filament terminal in receptacles 2 and 3 are connected to the lament terminal pins 7 and 8, and the plate terminal pin receptacle 4 is connected to the plate terminal pin 9, by means of the connections 28. When the wipin brush 12 is in contacting position with t e contact terminal 13, the radio frequency input source 23 of the wired radio tuner will, in eflect, be substituted for the radio frequency input source 21 of the space radio receiver. When the wiping brush 12 is moved into contacting POSltlOIl'OII contact terminal 14, the detector tube 17 will function in the usual manner in the space radio receiver, substantially as if the adapter were not present, the connections in the said adapter being of such small ca acitance, that the capacitance constants of t e said space radio receiver are not disturbed.

While I- have shown my adapter as used in combination with a three element electron discharge tube and supporting socket therefor of a space radio receiving system, employed in combination with an auxiliary tunmg system, it is possible, and within the scope of my invention, to provide electrical connections of small capacitance, associated with a switch in such an adapter for use with a four element electron discharge tube, or any other type of electron dischargetube, and in any preferred electrical arrangement. Therefore, I do not limit myself to the foregoin description of my invention, except as may e pointed out in the appended claim.

Having thus described the invention, what I claim as new andoriginal, and desire to se An adapter for use between an electron discharge tube and socket therefor comprising, an insulating structure, metal receptacles in said structure for receiving and supporting the terminal pins of said tube, terminal pins in said structure for insertion in said socket in substitution for the terminal pins of said tube, a switch mounted on said struccure by Letters Patent of the, United States tnre including a pair of contacts and a movable blade for selective engagement therewith, said blade being electrically connected with one of said receptacles, one of said contacts being electrically connected with one of said terminals, the other of saidcontacts being adapted for connection with an auxiliary circuit, and electrical connections respectively between the other of said receptacles and said terminal pins'of said adapter.

' ROBERT D.-DUNCAN, JR. 

